DE2142964C3 - Circuit arrangement for earth fault monitoring in telephone systems - Google Patents

Description

The invention is concerned with an arrangement 25 pen, the change in resistance of this component as can be evaluated for earth fault monitoring of a group of partial message signals,
subscriber lines in telecommunications systems. The visual identification of the participant with

The subscriber line leading to minus potential ground fault on the α-wire brings an essential Er- (a-wire) η Telephone systems may have to make things easier for the maintenance staff, since the light that occurs Earth faults are monitored. Identify the disturbed line individually in public lights Telephone networks extend subscriber-side subscriptions.

directions used, dis their operating current from the drawing shows an embodiment of a

refer to the official battery against earth. Since the circuit according to the invention, its details driving current of these facilities in the subscriber- in connection with their function explained who-circuit may not trigger a switching function are 35 den.

no relays in the live α line j outgoing traffic

built-in. In known participant circuits lies

a protective resistor in the subscriber's α line.

mers, and about a z. B. for 50 subscribers common relay R with earth via the contacts / 4 λ-winding, the same relay lying in series becomes in the event of a ground fault 40/3, 6-wire subscriber loop 7W-a-wire, ti, / 3, on Signal given. A ground fault on the α wire and the lamp L against minus Si . With the Konbci no or only very little line resistance '3, the central control is requested and, taking into account the voltage, the relay T is energized after selecting the connection path via the and resistance tolerances for a 60 V C-core. Relay T with Konbatterie switches on a maximum output of 5.5 watts to 45 cycles / 1 relay F. The contacts / 4 and / 3 form a protective resistor. If the structure is correct, the Relab R is ab. During the conversation, the mechanical size of the resistance and the Ah- the relays T and F are excited,
management of the heat occurring on the component very "»,, ,,,.

problematic. ² · Incoming traffic

Another disadvantage of the known device 50. Relay T is excited via the c-wire and with Kon-Hegt that there the common clock for 50 participants / 1 relay F is switched on,
the same monitoring relay responds to simultaneous pick-up of several subscribers and ³ - Incomplete initiation of a call;
Circumstances due to the transverse derivation of several continuous loops
Subscriber lines hold, although this cross-connection does not 55 If a subscriber does not hang up the actually permissible value in a financial case after the end of the conversation, or exceeds it. The main disadvantage of the known gene of a connection set is not selected, but the arrangement is that when the connection set is connected by disconnecting the c-wire, the monitoring relay is only switched off in an indicated manner. Relay T drops out and switches with the fact that one or more subscribers of a 50th 60 nen contacts / 4 and / 3 relays /? to the participant group have a defective line. Only through mer line. Relay R takes over with contact rl systematic checking of the subscriber lines the attitude of the F-relay after drop of 7-relays, the bad line can be recognized and the damage relay R gets its minus potential over the be repaired. actuated contact / 3 and the resistance WiI. With

The invention is based on the object of providing a 65 to the transmitter Ü will provide the subscriber via Kon circuitry that transmits the busy signal as a replacement for clock / 4. In the case of looping protective resistances for interrupting the earth fault, contact rl after monitoring has dropped into the subscriber connection circuit relay R the discharged capacitor C as a waste

delay switched on to relay F. If the subscriber loop remains interrupted for longer than about 12OmS, relay F drops out. When contact / 1 is actuated, a signal is emitted on wire UA via contact / 1.

4. Start of voting before switching

If the subscriber TN starts dialing before switching through, then the first time relay R drops with the discharged capacitor Γ relay F is energized. Relay F disconnects no 'contact / 5 the request for the central Siei ". _.ig up and the participant is transmitted with Koih '»» ^r i ι -i the busy signal.

5. F.rds / "ate at rest

If an earth f'lrQ occurs during the rest position, the lamp L, for example a communication lamp DIN 49 838 A, corresponding to the line resistance up to the earth connection point lights up and signals by changing the resistance value of the lighting-dependent resistor LDR on the wire LA den occurred error.

ft. earth fault during the conversation biw.
in the event of incomplete triggering

An earth fault E during the call releases the connection by shorting a feed relay

ίο off and by disconnecting the c-wire the relay T drops out. The response of relay R is prevented by the earth on wire α or b. After about 12OmS relay F also drops out and switches to lamp L with contact / 3. The resistance Wi 2 in the σ-wire is only briefly exposed to a high load and can therefore be designed for a low load (1 W). The other switching operations are the same as those described under point 5.

1 sheet of drawings

Claims (1)

is to be inserted and both the group monitoring patent claim: chung as well as the identification of the disturbed line permitted. Circuit arrangement for earth fault over- To solve this problem is according to the invention Monitoring of a subscriber line group, provided that in each outgoing line, characterized in that each outgoing line (α) going to the subscriber in the subscriber connection to the subscriber in the direction of the exchange facility has a terminal lamp connected to the subscriber connection Amtseinrich- is looped and that groups of these lamps so antung a small lamp (L) is looped in and that are arranged that one of this lamp group, groups of these lamps are arranged in such a way that> o an ordered, lighting-dependent resistor or one assigned to this lamp group, lighting- several lighting-dependent resistance (LDR) assigned to this group of lamps or several line-dependent resistors the lighting up of one or more lamps assigned to this lamp group through resistance-dependent resistors (LDR) signal the lighting up, whereby the earth-faulty part of one or more lamps through Disgusting »5 takers through that Luminous lamps identify a change in the status signal, whereby the can become grounded. short-term participants through the glowing brief current flow (as e.g. Lamp can be identified. a relay is required) changes the per se very low cold resistance of the lamp (about ac 400 o) not. A ground fault on the α wire is marked by the constant lighting of the lamp. net. A lighting-dependent resistor is structurally assigned to several lamps together in such a way that that when one or more lights